# Package io.netty.handler.codec.mqtt

Encoder, decoder and different Message Types for MQTT.

See: Description

Interface Summary
MqttMessageBuilders.PropertiesInitializer<T>

Class Summary
MqttConnAckMessage: See MQTTV3.1/connack
MqttConnAckVariableHeader: Variable header of `MqttConnectMessage`
MqttConnectMessage: See MQTTV3.1/connect
MqttConnectPayload: Payload of `MqttConnectMessage`
MqttConnectVariableHeader: Variable Header for the `MqttConnectMessage`
MqttConstant
MqttDecoder: Decodes Mqtt messages from bytes, following the MQTT protocol specification v3.1 or v5.0, depending on the version specified in the CONNECT message that first goes through the channel.
MqttEncoder: Encodes Mqtt messages into bytes following the protocol specification v3.1 as described here MQTTV3.1 or v5.0 as described here MQTTv5.0 - depending on the version specified in the first CONNECT message that goes through the channel.
MqttFixedHeader: See MQTTV3.1/fixed-header
MqttMessage: Base class for all MQTT message types.
MqttMessageBuilders
MqttMessageBuilders.AuthBuilder
MqttMessageBuilders.ConnAckBuilder
MqttMessageBuilders.ConnAckPropertiesBuilder
MqttMessageBuilders.ConnectBuilder
MqttMessageBuilders.DisconnectBuilder
MqttMessageBuilders.PubAckBuilder
MqttMessageBuilders.PublishBuilder
MqttMessageBuilders.SubAckBuilder
MqttMessageBuilders.SubscribeBuilder
MqttMessageBuilders.UnsubAckBuilder
MqttMessageBuilders.UnsubscribeBuilder
MqttMessageFactory: Utility class with factory methods to create different types of MQTT messages.
MqttMessageIdAndPropertiesVariableHeader: Variable Header containing, Packet Id and Properties as in MQTT v5 spec.
MqttMessageIdVariableHeader: Variable Header containing only Message Id See MQTTV3.1/msg-id
MqttProperties: MQTT Properties container
MqttProperties.BinaryProperty
MqttProperties.IntegerProperty
MqttProperties.MqttProperty<T>: MQTT property base class
MqttProperties.StringPair
MqttProperties.StringProperty
MqttProperties.UserProperties
MqttProperties.UserProperty
MqttPubAckMessage: See MQTTV3.1/puback
MqttPublishMessage: See MQTTV3.1/publish
MqttPublishVariableHeader: Variable Header of the `MqttPublishMessage`
MqttPubReplyMessageVariableHeader: Variable Header containing Packet Id, reason code and Properties as in MQTT v5 spec.
MqttReasonCodeAndPropertiesVariableHeader: Variable Header for AUTH and DISCONNECT messages represented by `MqttMessage`
MqttSubAckMessage: See MQTTV3.1/suback
MqttSubAckPayload: Payload of the `MqttSubAckMessage`
MqttSubscribeMessage: See MQTTV3.1/subscribe
MqttSubscribePayload: Payload of the `MqttSubscribeMessage`
MqttSubscriptionOption: Model the SubscriptionOption used in Subscribe MQTT v5 packet
MqttTopicSubscription: Contains a topic name and Qos Level.
MqttUnsubAckMessage: See MQTTV3.1/unsuback
MqttUnsubAckPayload: Payload for MQTT unsuback message as in V5.
MqttUnsubscribeMessage: See MQTTV3.1/unsubscribe
MqttUnsubscribePayload: Payload of the `MqttUnsubscribeMessage`

Enum Summary
MqttConnectReturnCode: Return Code of `MqttConnAckMessage`
MqttMessageType: MQTT Message Types.
MqttProperties.MqttPropertyType
MqttQoS
MqttSubscriptionOption.RetainedHandlingPolicy
MqttVersion: Mqtt version specific constant values used by multiple classes in mqtt-codec.

Exception Summary
MqttIdentifierRejectedException: A `MqttIdentifierRejectedException` which is thrown when a CONNECT request contains invalid client identifier.
MqttUnacceptableProtocolVersionException: A `MqttUnacceptableProtocolVersionException` which is thrown when a CONNECT request contains unacceptable protocol version.

## Package io.netty.handler.codec.mqtt Description

Encoder, decoder and different Message Types for MQTT.